diff --git a/sys/include/aml.h b/sys/include/aml.h
index d1864a60c..27c31d003 100644
--- a/sys/include/aml.h
+++ b/sys/include/aml.h
@@ -36,6 +36,7 @@ void		amldrop(void *);
 
 void*		amlroot;
 int		amldebug;
+uvlong		amlintmask;
 
 #pragma	varargck	type	"V"	void*
 #pragma	varargck	type	"N"	void*
diff --git a/sys/src/9/pc/archacpi.c b/sys/src/9/pc/archacpi.c
index 644df59b9..c2ed1580f 100644
--- a/sys/src/9/pc/archacpi.c
+++ b/sys/src/9/pc/archacpi.c
@@ -495,6 +495,7 @@ acpiinit(void)
 	for(i=0; i<ntblmap; i++){
 		t = tblmap[i];
 		if(memcmp(t->sig, "DSDT", 4) == 0){
+			amlintmask = (~0ULL) >> (t->rev <= 1)*32;
 			amlload(t->data, tbldlen(t));
 			break;
 		}
diff --git a/sys/src/cmd/scram.c b/sys/src/cmd/scram.c
index d35d48235..be5f2de40 100644
--- a/sys/src/cmd/scram.c
+++ b/sys/src/cmd/scram.c
@@ -69,8 +69,10 @@ loadacpi(void)
 		t = realloc(t, sizeof(*t) + l);
 		if(readn(fd, t->data, l) != l)
 			return -1;
-		if(memcmp("DSDT", t->sig, 4) == 0)
+		if(memcmp("DSDT", t->sig, 4) == 0){
+			amlintmask = (~0ULL) >> (t->rev <= 1)*32;
 			amlload(t->data, l);
+		}
 		else if(memcmp("SSDT", t->sig, 4) == 0)
 			amlload(t->data, l);
 		else if(memcmp("FACP", t->sig, 4) == 0){
diff --git a/sys/src/libaml/aml.c b/sys/src/libaml/aml.c
index 7c513f89b..64b17bf12 100644
--- a/sys/src/libaml/aml.c
+++ b/sys/src/libaml/aml.c
@@ -296,7 +296,7 @@ mki(uvlong i)
 	uvlong *v;
 
 	v = mk('i', sizeof(uvlong));
-	*v = i;
+	*v = i & amlintmask;
 	return v;
 }
 
@@ -2139,6 +2139,9 @@ amlinit(void)
 	fmtinstall('V', Vfmt);
 	fmtinstall('N', Nfmt);
 
+	if(!amlintmask)
+		amlintmask = ~0ULL;
+
 	n = mk('N', sizeof(Name));
 	n->up = n;